1. Field of Invention
The present invention relates to azeotrope-like compositions. More particularly, the invention relates to ternary azeotrope-like compositions comprising hydrohalocarbons and hydrogen fluoride.
2. Description of Prior Art
Fluorocarbon based fluids have found widespread use in industry in a number of applications, including as refrigerants, aerosol propellants, blowing agents, heat transfer media, gaseous dielectrics, fire suppression with or without extinguishing and fire/explosion prevention. However, certain compounds, such as chlorofluoroalkanes and hydrochlorofluoroalkanes are suspected of depleting atmospheric ozone and, thus, are harmful to the environment. Moreover, some of these compounds are believed to contribute to global warming. Accordingly, it is desirable to use halocarbon fluids having low or even zero ozone depletion potential and low global warming potential, such as the entgegen isomer of 1-chloro-3,3,3-trifluoropropene (i.e., E-1-chloro-3,3,3-trifluoropropene or “1233zd(E)”).
1233zd(E) has been found to have a wide variety of uses, for example as a heat transfer agent, as a foaming agent, and as a solvent, among other uses, see, e.g., U.S. Patent Publication Nos. 2008/0098755 and 2008/0207788, and U.S. Pat. No. 6,362,383. 1233zd may be produced by a number of different methods. For example, U.S. Pat. Nos. 5,710,352, 6,111,150, 7,829,747 describe several methods for making 1233zd. Each of the abovementioned publications are herein incorporated by reference in their entirety.
The use of single component fluids or azeotropic mixtures, which do not fractionate on boiling and evaporation, is also desirable. Of particular interest are mixtures containing hydrofluorocarbons, chlorofluoroolefins, and hydrogen fluoride (HF) which are useful in the preparation and/or purification of desirable hydrofluorocarbons and chlorofluoroolefins products. Unfortunately, the identification of new, environmentally-safe, non-fractionating mixtures is complicated due to the fact that azeotrope formation is not readily predictable.
Binary azeotropes between 1233zd and HF, between 1,1,1,3,3-pentafluoropropane (245fa) and HF and between 245fa and 1233zd(E) are known and have been described in U.S. Pat. Nos. 6,013,846, 6,328,907 and 7,183,448, respectively, each of which are incorporated herein by reference. However, there remains a need for ternary azeotropes containing hydrofluorocarbons, chlorofluoroolefins, and HF. Such mixtures are the subject of this invention.